A sign for the Lucky Friday Mine is posted outside the mine in Mullan, Idaho, Saturday, April 16, 2011. An official with the Hecla Mining Company says a rescue operation is under way Saturday at the mine in northern Idaho. One miner reportedly is missing. (AP Photo/KHQ-TV)— AP

A sign for the Lucky Friday Mine is posted outside the mine in Mullan, Idaho, Saturday, April 16, 2011. An official with the Hecla Mining Company says a rescue operation is under way Saturday at the mine in northern Idaho. One miner reportedly is missing. (AP Photo/KHQ-TV)
/ AP

BOISE, Idaho 
Rescuers faced mounting obstacles Monday as they tried to reach an Idaho silver miner trapped a mile underground: They will need more equipment, need to clear more than twice as much debris and must dislodge boulders that stand in the way.

The effort to reach 30-year mining veteran Larry Marek had stretched into a third day after he was trapped when the roof of a tunnel collapsed about 5:30 p.m. Friday at the Lucky Friday mine in Mullan. Officials did not know Marek's condition, and they have not had contact with him since the collapse.

"It's been very different every day," said Melanie Hennessey, spokeswoman for Hecla Mining, where Marek has worked for 12 years. "That's because of the complexity of the fallen ground."

The company also was deploying a diamond drill to determine if there is an open area behind the cave-in that could have provided Marek with refuge. A 2-inch hole from the drill could allow fresh air into the area, though it may take as long as two days to bore from a nearby tunnel through about 185 feet of rock, Hennessey said.

The accident Friday comes as a spike in silver prices boosts the Coeur d'Alene company's mining of the precious metal.

Silver prices have soared about 38 percent this year, and Hecla is spending $200 million to increase silver production by about 60 percent. It is expanding the historic Lucky Friday mine, tucked into the forested mountains of the Idaho Panhandle's Silver Valley, and extending its life beyond 2030.

Like mining areas around the world, northern Idaho is not immune to accidents, some of them tragic. Last June, a miner was killed in the Galena Mine in nearby Silverton after a rock slab fell on him.

In 1972, 91 miners were killed in a fire about 3,700 feet underground inside the Sunshine Mine between Kellogg and Wallace.

In the Lucky Friday mine, workers engaged Monday in the time-consuming task of shoring up the caved-in tunnel to prevent another collapse, and officials said a crew had placed timber supports in only an additional several feet over a span of about 12 hours.

"The amount of work needed to do the 4 feet, given the increase in height, is tremendous," Hennessey said, adding the speed of the advance depends on the material rescuers encounter.

Hecla Mining officials said Monday that workers had advanced a total of 39 feet into the collapsed area, which could be as long as 75 feet. The ground that fell is up to 25 feet high and 20 feet wide, more than twice as high previously thought. Hecla officials said that's made shoring up the tunnel to make it safe for rescue workers more complex and time-consuming.

Workers, who had lowered a remote-controlled digging machine called a mucker to speed rescue efforts, also were awaiting the arrival of an electrical component before they could employ a digger with larger capacity.

It's unclear if Marek had communication equipment with him at the time of the accident; it could have been left in a vehicle he was using at the time.